Method of using a drill in sand control liner

FIELD OF THE INVENTION

The field of the invention is liners that are rotated to drill without a drill string and more particularly where the liners have openings with sand control devices and the openings are unsealed after drilling is complete.

BACKGROUND OF THE INVENTION

Saving trips into the well saves the well operator money. One such time saving technique that has been developed is running a liner with screens on a drill string so that as the bit advances so does the liner. When the desired location is reached, the drill string up to the bit is released from the bit that is rotatably mounted to the liner. The liner doesn't rotate as the bit turns. After the drill string is disconnected from the bit and removed, a swage can be run in to expand the screen or an isolation packer and a crossover can be run in and a gravel pack operation can be performed. This technique is illustrated in U.S. Pat. No. 7,108,083. The bit can be driven by a drill string or a downhole motor supported by coiled tubing.

Drill strings have been used with screens in the liner when running in liner while drilling the hole because of the need to deliver pressurized drilling mud to the bit nozzles to displace the drill cuttings and cool the bit. Since the screen is an open structure, it has not been practical to deliver liner while making hole without using a drill string inside the liner so that pressurized mud can be directly delivered to the bit while the drill string supports the liner in a manner where the liner doesn't see fluid pressure in advance of the bit.

In trying to eliminate the drill string and rotate a bit with a liner, particularly a liner that has screens or an array of slots, the problem that is confronted is the limited ability of such a structure to tolerate the applied torque from drilling and how to make the structure a conductor of pressurized fluid so that the bit nozzles could be supplied with cooling fluid and a means to get drill cuttings out of the way. Another consideration is to avoid perforation using explosives as it can cause damage to sensitive formations and the perforating guns can become stuck after detonation in low bottom hole pressure wells. The present invention solves these problems by providing a robust liner structure that can withstand the applied torque and drive the bit while still having the capability to convey pressure to the bit nozzles and when drilling is concluded to open passages with sand control features so that production can begin with the liner suspended and sealed to an existing and cemented well tubular. These and other features of the present invention will be more readily apparent from a review of the description of the preferred embodiment and the associated drawing while recognizing that the claims determine the full scope of the invention.

SUMMARY OF THE INVENTION

A liner rotates a bit to make more hole. The liner has openings with inserts in them to lend torque resistance to the liner. The inserts have a passage with a sand control media in the passage and a seal so that the liner can hold pressure for run in to get proper circulation through the bit. When a sufficient hole is made, the liner is hung off an existing cemented tubular and the seal for the passages within the sand control media is removed by a variety of techniques so that the formation can be produced in a single trip.

BRIEF DESCRIPTION OF THE DRAWING

<figref idrefs="DRAWINGS">FIG. 1</figref> is a section view of the tubular making hole with the bit at the bottom and a detailed view of an insert in one of the openings.

<figref idrefs="DRAWINGS">FIG. 1</figref><i>a </i>is an enlarged view of the insert.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

<figref idrefs="DRAWINGS">FIG. 1</figref> shows a casing <b>10</b> that has been cemented in wellbore <b>12</b>. Wellbore <b>12</b> is drilled with bit <b>14</b> secured to liner string <b>16</b> in a manner where they rotate in tandem. Near the top <b>17</b> of the string <b>16</b> is a liner hanger <b>18</b> of a type well known in the art. When the wellbore <b>12</b> is drilled, the hanger <b>18</b> with its slips and seal can be actuated so that the string <b>16</b> is supported by the casing <b>10</b>. A run in string <b>20</b> delivers the liner string <b>16</b> through the casing <b>10</b> in drilling the hole <b>12</b> to drive the bit <b>14</b> by virtue of a releasably and rotationally locked latch connection <b>37</b> of a type well known in the art.

String <b>16</b> has an array of holes <b>22</b> with internal threads <b>24</b> to allow securing insert <b>26</b> at its threads in holes <b>22</b>. Inserts <b>26</b> can be welded into position but a threaded connection is preferred as it is cheaper to assemble and allows fast removal for replacement of any inserts <b>26</b> when needed. Each insert <b>26</b> has a passage <b>28</b> therethrough. Inside passage <b>28</b> is a sand control medium <b>30</b> that is preferably sintered metal beads compatible with the anticipated well fluids and conditions. Illustratively shown for a single opening but present in all openings <b>22</b> is a sealing material <b>32</b> so that pressurized drilling mud delivered through run in string <b>20</b> is retained in the liner <b>16</b> and communicated to bit <b>14</b> to allow it to drill. Bit <b>14</b> may be releasably mounted to the lower end <b>34</b> of the liner <b>16</b> and run in string <b>20</b> can have a gripping mechanism, shown schematically as <b>36</b> at its lower end. The gripping mechanism <b>36</b> can grab the bit <b>14</b> which can be of a collapsible design so that it can be retrieved back through the liner <b>16</b> when drilling is done. Alternatively, the run in string <b>20</b> can also include a swage, shown schematically as <b>38</b> so that at the conclusion of drilling, the liner <b>16</b> can be expanded in the same trip. If the liner is expanded, the bit <b>14</b> need not have a collapse feature to be removed through it after expansion.

In drilling the wellbore <b>12</b>, the run in string <b>20</b> and the liner <b>16</b> are rotated to turn the bit <b>14</b> to make the hole <b>12</b>. The sealing material <b>32</b> initially plugs the passages <b>28</b> so that pressurized drilling mud can be delivered to the bit <b>14</b> to carry away cuttings. Drilling continues until the proper depth is reached or until the pressures downhole get so high as to risk fluid loss into the formation and an inability to clear cuttings away from the bit. At that point the sealing material <b>32</b> is removed. Depending on what material is selected for sealing, it can be removed in a variety of ways without string rotation. It can be dissolved, chemically attacked or simply designed to go away after prolonged exposure to well fluids or conditions. It can also be removed with a stimulus such as heat applied in the well. The removal, either partial or total of the sealing material <b>32</b> allows production to come through the sand control medium <b>30</b> and into the liner <b>16</b>. The well fluids can go to the surface through a production string and packer that replace the run in string <b>20</b> or alternatively, production can be taken through the run in string <b>20</b> itself saving another two trips for removing the run in string <b>20</b> and replacing it with a production string and packer (not shown). If expansion of the liner string <b>16</b> is contemplated, it can be done before the sealing material <b>32</b> is removed or after but preferably before production to the surface is allowed to start. If the bit <b>14</b> is to be retrieved then it should be done before production begins. The liner string <b>16</b> can be set on bottom before production begins or it can have its lower end <b>34</b> closed off to flow by other means.

Those skilled in the art will appreciate that a liner string <b>16</b> is presented that has the strength in torsion to operate a bit <b>14</b> and has the capability of selectively retaining pressure during drilling so that fluid can be forced through the bit nozzles while drilling. Perforating the liner for production access is not required in this situation. The sealing devices <b>32</b> are made to go away when drilling is concluded to provide access to production in passages <b>28</b>. Expansion of the liner <b>16</b> is possible in a single trip as is the ultimate capture and retrieval of the bit <b>14</b> through the liner <b>16</b> regardless of whether the liner is expanded or not. The openings <b>22</b> can be threaded in the wall or welded. The interior wall <b>40</b> should preferably be smooth with no internal projections if expansion is contemplated. Various known swages and expansion techniques can be used. The number and layout of openings <b>22</b> as well as their size can vary depending on the anticipated production rates.

The above description is illustrative of the preferred embodiment and many modifications may be made by those skilled in the art without departing from the invention whose scope is to be determined from the literal and equivalent scope of the claims below.